【論文・アクセプト済み】列車(中国の高速鉄道)の乗客におけるCOVID-19感染のリスク：疫学およびモデリング研究(2020.7.31作成)

A Marm Kilpatrick @DiseaseEcology

Would love to hear counter-arguments that show that at least some transmission occurred on the train, especially from authors. Most convincing, noted above, would be fig of attack rate vs distance (row, column) for two types of passengers - those sharing destinations & not.

A Marm Kilpatrick @DiseaseEcology

If spatial pattern (higher risk for closer seats & especially in adjacent seats) is robust for passengers that don't share to-from destinations then evidence for transmission strong. If no pattern (like travel duration) then no evidence for transmission on train.

A Marm Kilpatrick @DiseaseEcology

Addition: @mlipsitch pointed me to Table S3 (which I somehow missed) which shows same data as Fig S3 above, except for all trip durations. Also shows that high attack rate for adjacent seat & 5-8 hr trips drops to 0(!) when not including passengers w/ same To/From destinations. pic.twitter.com/BlVhELU2l3

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A Marm Kilpatrick @DiseaseEcology

In making plot in tweet above (shown again here) I realized diff in scales in 2 panels Fig S3 above (which I didn't notice at first). Not only is there no increase w/ trip duration but attack rate is ~0 for all durations for different itineraries/strangers. pic.twitter.com/ekcCZdCYTD

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A Marm Kilpatrick @DiseaseEcology

Would love comment from authors but this is pretty strong evidence to me that ~ZERO transmission is occurring on train & attack rate patterns on train just reflect seating choices of people from same household/friend/work circle & off-train is where transmission is happening.